1. Field of the Invention
The present invention relates to the obtaining of an external trigger for an oscilloscope and, more particularly, obtaining such an external trigger for observing video waveforms.
2. Description of the Prior Art
When a television receiver is to be serviced, it is necessary to obtain an external trigger signal for observing video waveforms on an oscilloscope. At present this trigger signal is derived by direct electrical contact from the horizontal or vertical synchronization circuits of the receiver. It is thus necessary that the serviceman knows where in the receiving circuitry the horizontal and vertical synchronization signals are available. To obtain this knowledge is time consuming, particularly when the serviceman is required to maintain and/or repair different models and brands of television receivers. In addition, the high voltage present in the horizontal output stage constitutes a danger of physical injury to the serviceman.